It's the algorithm's fault for not listening to my "mute this person". I had my feed muted so I didn't see any posts (which is how I wanted it), but now I see random "recommended" content, with no way I can see to opt out. That's not my fault.

This is like complaining that a blog site shows you blog posts. It's made for this purpose, not yours. Using it is your choice - don't.

FB has an entire team of very well paid people whose entire job is to tweak this algorithm. Presenting relevant content is the whole concept. I suspect where it goes wrong is chasing “engagement” at all costs despite whether it’s emotionally pleasant to the viewer. FB doesn’t care if I actually like the content they present - just whether it keeps me on the site longer. That is, I believe, a poor choice since, at least in my case, it led me to stop using their service.